Process for the manufacture of black carbonaceous pigment



Patented Feb. 27, I923,-

VER'NGN H. SCHNEE, GE ITEACA, NEW YORK.

PROCESS FOR THE MANUFACTURE OF BLACK CABBON'ACEOUS PIGMENT'.

Ill'o Drawing.

To all wh'om it may concern:

Be it known that I, VERNON H. SGHNEE, a citizen of the United States,residing at Ithaca, in the county of Tompkins and State v of New York,have invented a certain new and useful Process for the Manufacture ofBlac'k Carbonaceous Pigment, of which the following is a true and exactspecification;

My invention rel-ates to a process for the manufacture of blackcarbonaceous pigment by the decomposition of carbon monoxide gas, andhas for its object to produce such a pigment superior in quality to theblack carbonaceous pigments now manufactured and used, and incidentally.to render "the process for making black carbonaceous pigmentconsiderably cheaper and independent of the supply of naturalhydrocarbon gases. I

As is well known, the black carbonaceous pigment which is known and usedcommercially under the name of carbon black consists essentially offinely divided carbon obtained by the partial combustion of hydro carbongases, as, for example, natural gas, in-

cooler,'wh1ch;reduces the temperature of the a supply of airinsuflicient for the complete combustion of the hydrocarbons in the gas.This process for the manufacture of black carbonaceous pigment is knownto be inefficient, since only a relatively small proportion of thecarbon contained in the hydrocarbons of the original gas is recovered inthe black pigment obtained therefrom. Moreover, the supply ofhydrocarbon gases, particularly natural gas, available for use in the.manufacture of black carbonaceous pigments is steadily decreasing andwill be insufficient to meet the commercial demand within acomparatively short time.

I have found that a black carbonaceous pigment consisting essentially ofcarbon in a finely divided condition, is obtained when carbon monoxidegas is caused to decompose into carbon dioxide gas and carbon attemperatures above 300 degrees centigrade and below 800 degreesoentigrade. This product is superior in covering power and in hidingpower to the black carbonaceous pigments, as for example, carbon black,which are obtained by the partial combustion of hydrocarbon gases. 7 p 1I have found that this decomposition of carbon monoxide gas andthe-resulting1 formation of black carbonaceous pigment takes place muchmore readily and much more rapidly when the carbon monoxide is atemperature of 750 degrees centigrade.

Application filed January 2c, 1922. seiiai No. 530,660.

brought in contact with a suitable catalyst.

As catalysts for this decomposition, I prefer to use a metal of theeighth group of the periodic table,"- as, for example, cobalt metal.Moreover, I have found that the decomposition of the carbon monoxide gasand the formation of the black carbonaceous pigment occurs more readilyand proceeds more nearly tocompletion if the carbon monoxide gas ismaintained under pressures higher than atmospheric pressure. I havefound also that black carbonaceous pigment is formed not only when purecarbon monoxide gas is caused to decompose, but also When carbonmonoxide in admixture with inert gases is caused to decompose. I havefound also that the admixture of hydrogen with the carbon monoxide gashas no deleterious effect and even increases the yield of 'blackcarbonaceous pigment from the gas.

gas mixture to 750 degrees centigrade. I then pass this gas mixturethrough a compressor which compresses the gas to a pressure of 50 poundsper square inch. The

gas is then passed .under this pressure through a screen of cobalt metalwlre contained in a reaction chamber malntained at The reaction productsare then cooled and allowed .to escape through a collection chamher, inwhich the finely divided black carbonaceous pigment is collected andrecovered, while the waste gas is allowed to escape into the air.

It is understood that this example. is given I merely to describe onemethod of practicing my invention, and that I do not-restrlct myself tothe specific apparatus, or the specific conditions described in thisexample.

Having thus described my mventlon, I claim asnew and desire to secure byLetters Patent: I

1. The process of manufacturing black carbonaceous pigment by thedecomposition of carbon monoxide gas at temperatures above 300 degreescentigrade and below 800 degrees centigrade and in the presence of acatalyst consisting of, a metal of the eighth group of the periodictable.

2. The process of manufacturing black than atmospheric pressure.

carbonaceous pigment by the decomposition 4 carbonaceous pigment by thedecomposition of carbon monoxide gas at temperatures ab0ve'300 degreescentigrade and below 800 degrees centigrade, in the presence of cobalt.metal as a catalyst.

3. The process of manufacturing black of carbon monoxide gas attemperatures above 300 degrees centigrade and below 800 degreescentigrade, and at pressures greater mospheric pressures.

5. The process of manufacturing black carbonaceous pigment by thedecomposition of carbon monoxide gas at temperatures above 300 degreescentigrade and below 800 degrees centigrade, in the presence of acatalyst consisting of a metal of theeighth group of the periodic table,and at pressures greater than atmospheric pressure.

6. The process of manufacturing black carbonaceous pigment by thedecomposition of carbon monoxide gas at temperatures above 300 degreescentigrade and below 800 degrees centigrade, in the presence of cobaltmetal as a catalyst, and at pressures greater than atmospheric pressure.p

.7. The process of manufacturing black carbonaceous pigment by bringinga gaseous mixture containing carbon monoxide into contact with acatalyst at temperatures above 300 degrees centigrade and below 800degrees centigrade.

8. The process of manufacturing black carbonaceous pigment by bringing agaseous mixture containing carbon monoxide into contact with a metal ofthe eighth group of the periodic table, at temperatures above 300degrees centigrade and below 800 degrees centigrade.

9. The process of manufacturing black carbonaceous pigment by bringing agaseous mixture containing carbon monoxide into contact with cob-altmetal, at temperatures above 300 degrees centigrade and below 800degrees centigrade.

V H. SCHNEE.

Witnessed by- FRED H. RHODES.

